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Assessment of a photon‐counting detector for a dual‐energy C‐arm angiographic system
Author(s) -
Ahmad Moiz,
Fahrig Rebecca,
Pung Leland,
Spahn Martin,
Köster Niko S.,
Reitz Silke,
Moore Teri,
Choi JangHwan,
Hinshaw Waldo,
Xia Yan,
Müller Kerstin
Publication year - 2017
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1002/mp.12517
Subject(s) - imaging phantom , detector , calibration , image quality , photon counting , flat panel detector , fluoroscopy , optics , projection (relational algebra) , photon , image sensor , medical imaging , physics , nuclear medicine , medical physics , computer science , artificial intelligence , medicine , image (mathematics) , algorithm , quantum mechanics , nuclear physics
Purpose This article presents the implementation and assessment of photon‐counting dual‐energy x‐ray detector technology for angiographic C‐arm systems in interventional radiology. Methods A photon‐counting detector was successfully integrated into a clinical C‐arm CT system. Detector performance was assessed using image uniformity metrics in both 2D projections and 3D cone‐beam computed tomography (CBCT) images. Uniform exposure fields were acquired to analyze projection images and scans of a homogeneous cylinder phantom were taken to analyze 3D reconstructions. Image uniformity was assessed over a broad range of imaging parameters. Results Detector calibration greatly improved image uniformity, reducing image variation from 8.8% to 0.5% in an ideal scenario, but image uniformity degraded when imaging parameters varied strongly from values set at calibration: the tube voltage, low‐high energy threshhold, and tube current had the greatest impact. Material discrimination and dynamic angiography capabilities were successfully demonstrated in separate phantom and in vivo experiments. Conclusion The uniformity results identified major factors degrading image quality. The quantitative results will guide selection of calibration points to mitigate the loss of uniformity. The unique combination of dual‐energy and fluoroscopy imaging capabilities with a flat‐panel photon‐counting detector may enable new applications in interventional radiology.